Ectasia following laser in situ keratomileusis

There is perhaps no issue in refractive surgery as controversial as ectasia following laser in situ keratomileusis (LASIK). While this complication is rare, the recognition of risk factors to reduce and perhaps eliminate postsurgical ectasia is important for all ophthalmologists. To better understand the issue, a committee of corneal and refractive surgeons from the American Academy of Ophthalmology, the International Society of Refractive Surgery, and the American Society of Cataract and Refractive Surgery put forth a consensus opinion on post-LASIK ectasia (“Keratoconus and Corneal Ectasia After LASIK,” pages 2035–2038). Among the key points discussed in the paper is that clinical findings in the preoperative evaluation of the refractive patient present a continuum from the clearly normal to the clearly pathologic cornea. The difficultly is that in many patients, the clinical findings are somewhere in the middle of this ambiguous continuum and based on previous and current knowledge, it is impossible to predict which patients will do well with laser vision correction and which will develop ectasia. Risk factors for the development of ectasia after LASIK have been proposed. However, these risk factors are based largely on anecdotal retrospective analysis. Furthermore, no factor provides a quantitative analysis of the risk to patients that they will develop ectasia with or without surgery and of the actual visual prognosis. One important factor that should be addressed is that the knowledge base of refractive surgery outcomes has changed over the years. The first case of post-LASIK ectasia was not reported until 1998, and it was not until after 2000 that a significant number of cases had been described in the literature. Our personal experience and that of our peers and the ophthalmic literature have dramatically changed over the past 5 years and so has the “standard of care.” We will continue to gain knowledge about long-term outcomes and should expect the standard of care to change accordingly. WHAT PATIENTS ARE AT RISK? Precise data to guide refractive surgeons to advise patients on the continuum are not available. How much steepening is safe? How much asymmetry in topography is within the normal range? How much corneal thinning is acceptable? Can photorefractive keratectomy be performed in these patients without the risk for ectasia? Confounding the issue is that most refractive surgeons have patients with preoperative risk factors by today's standards, such as inferior steepening, asymmetric astigmatism, and/or steep corneas, who have had excellent results. Furthermore, ectasia has occurred in patients with no discernible preoperative risk factors. What Is Needed? Additional data are essential to improve our ability to advise patients on the safety and risks of laser vision correction. We need a database to compile accurate preoperative and postoperative information. Data on 2 groups of patients should be gathered: (1) all cases of post-laser ectasia and (2) cases that were at high risk for ectasia by today's standards but have had excellent results. With this additional information, we will have a better understanding of which patients are appropriate and which are at risk. An understanding of the quantitative risk for ectasia will allow our patients to make informed decisions. In the interim, the consensus opinion in this issue consolidates useful information for the clinician and provides a starting point for future evaluation.